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https://www.readbyqxmd.com/read/29781119/the-effect-of-lifelong-exercise-frequency-on-arterial-stiffness
#1
Shigeki Shibata, Naoki Fujimoto, Jeffrey L Hastings, Graeme Carrick-Ranson, Paul S Bhella, Christopher Hearon, Benjamin D Levine
Central arterial stiffness increases with sedentary aging. While near-daily, vigorous lifelong (>25 yr) endurance exercise training prevents arterial stiffening with aging, this rigorous routine of exercise training over a lifetime is impractical for most individuals. The aim was to examine whether a less frequent 'dose' of lifelong exercise training (4-5 sessions/wk for > 30 min) that is consistent with current physical activity recommendations elicits similar benefits on central arterial stiffening with aging...
May 20, 2018: Journal of Physiology
https://www.readbyqxmd.com/read/29779953/a-quality-assurance-device-for-measuring-afterloader-performance-and-transit-dose-for-nasobiliary-high-dose-rate-brachytherapy
#2
Christopher L Deufel, John P Mullins, Mark J Zakhary
PURPOSE: Nasobiliary high-dose-rate (HDR) brachytherapy has emerged as an effective tool to boost the radiation dose for patients with unresectable perihilar cholangiocarcinoma. This work describes a quality assurance (QA) tool for measuring the HDR afterloader's performance, including the transit dose, when the source wire travels through a tortuous nasobiliary catheter path. METHODS AND MATERIALS: The nasobiliary QA device was designed to mimic the anatomical path of a nasobiliary catheter, including the nasal, stomach, duodenum, and bile duct loops...
May 17, 2018: Brachytherapy
https://www.readbyqxmd.com/read/29776892/technique-for-the-administration-of-high-dose-rate-brachytherapy-to-the-bile-duct-using-a-nasobiliary-catheter
#3
Christopher L Deufel, Keith M Furutani, Robert A Dahl, Michael P Grams, Luke B McLemore, Christopher L Hallemeier, Michelle Neben-Wittich, James A Martenson, Michael G Haddock
PURPOSE: Cholangiocarcinoma patients who are potential candidates for liver transplantation may be treated with high-dose-rate (HDR) brachytherapy using a minimally invasive nasobiliary catheter in an effort to escalate the radiotherapy dose to the tumor and maximize local control rates. This work describes the equipment, procedures, and quality assurance (QA) that enables successful administration. METHODS AND MATERIALS: This work describes the nasobiliary catheter placement, simulation, treatment planning, treatment delivery, and QA...
May 16, 2018: Brachytherapy
https://www.readbyqxmd.com/read/29776831/3d-brachytherapy-for-cervical-cancer-new-optimization-ways
#4
I Fumagalli, C Haie-Méder, C Chargari
Brachytherapy has known major improvements in recent decades. It represents an essential component of local treatment of cervix cancers. One major breakthrough was the advent of 3D imaging for image-guided brachytherapy. Doses could be prescribed to volumes. This allows better delineation and coverage of target volumes, as well as organs at risk (bladder, rectum, sigmoid) protection. Local recurrences have been consequently reduced and survival has been improved. In addition, improvement and development of new applicators have facilitated the delivery of interstitial treatments...
May 15, 2018: Cancer Radiothérapie: Journal de la Société Française de Radiothérapie Oncologique
https://www.readbyqxmd.com/read/29776826/recognition-of-sympathetic-crashing-acute-pulmonary-edema-scape-and-use-of-high-dose-nitroglycerin-infusion
#5
Samantha Paone, Leigha Clarkson, Billy Sin, Sheena Punnapuzha
Sympathetic Crashing Acute Pulmonary Edema (SCAPE), or flash pulmonary edema, is the extreme end of the acute pulmonary edema spectrum. A sympathetic surge occurs as a result of decreased systemic perfusion resulting in further increases in afterload, causing the patient to decompensate. Patients can decompensate quickly, therefore patients require rapid interventions. The use of high-dose nitroglycerin (HDN) has been a topic of interest as it is believed to achieve preload and afterload reduction. However, its use continues to be controversial due to concerns of drug induced hypotension, syncope or paresthesia...
May 10, 2018: American Journal of Emergency Medicine
https://www.readbyqxmd.com/read/29775415/exercise-cardiac-mri-unmasks-right-ventricular-dysfunction-in-acute-hypoxia-and-chronic-pulmonary-arterial-hypertension
#6
Shareen Kaur Jaijee, Marina Quinlan, Pawel Tokarczuk, Matthew Clemence, Luke S Howard, J Simon R Gibbs, Declan O'Regan
Background - Coupling of right ventricular (RV) contractility to afterload is maintained at rest in the early stages of pulmonary arterial hypertension (PAH), but exercise may unmask depleted contractile reserves. We assessed whether elevated afterload reduces RV contractile reserve despite compensated resting function using non-invasive exercise imaging. Methods and Results - Fourteen patients with PAH (mean age 39.1 years, 10 females) and 34 healthy control subjects (mean age 35.6 years, 17 females) completed real-time cardiac magnetic resonance imaging during sub-maximal exercise breathing room-air...
May 18, 2018: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/29756656/pathophysiology-and-treatment-of-achalasia-in-a-muscle-mechanical-perspective
#7
REVIEW
Hans Gregersen, Kar Man Lo
This review provides a biomechanical perspective on the pathophysiology and treatment of achalasia. The esophagus is efficient in transporting ingested material to the stomach in healthy subjects. A fine balance exists between the peristaltic forces generated in the esophageal body (which herein is defined as the preload) and the resistance in the outlet, the esophago-gastric junction (which is defined as the afterload). Achalasia is a rare esophageal disease that progressively over many years challenges esophageal efficacy...
May 14, 2018: Annals of the New York Academy of Sciences
https://www.readbyqxmd.com/read/29748074/-altitude-and-the-right-heart
#8
REVIEW
R Naeije
INTRODUCTION: Altitude is associated with a decrease in partial pressure of oxygen. Hypoxia induces pulmonary vasoconstriction with subsequent fixed increase in pulmonary artery pressure, and eventual right heart failure. CURRENT KNOWLEDGE: High altitude exposure is associated with an increase in pulmonary artery pressure that is proportional to initial vasoconstriction. Echocardiographic evaluations on a large number of subjects show that the altitude-induced increase in pulmonary pressure is generally modest and does not exceed the 25mmHg that are diagnostic of pulmonary hypertension...
May 7, 2018: Revue des Maladies Respiratoires
https://www.readbyqxmd.com/read/29746007/preterm-growth-restriction-and-bronchopulmonary-dysplasia-the-vascular-hypothesis-and-related-physiology
#9
Arvind Sehgal, Stella M Gwini, Samuel Menahem, Beth J Allison, Suzanne L Miller, Graeme R Polglase
KEY POINTS: Approximately 5-10% pregnancies are affected by fetal growth restriction. Preterm infants affected by fetal growth restriction have a higher incidence of bronchopulmonary dysplasia. This study is the first to measure pulmonary artery thickness and stiffness. It highlights that impaired vasculogenesis may be a contributory factor in the higher incidence of bronchopulmonary dysplasia in preterm growth restricted infants. The study addresses the mechanistic link between fetal programming and vascular architecture and mechanics...
May 10, 2018: Journal of Physiology
https://www.readbyqxmd.com/read/29727214/hemodynamic-effects-of-incremental-lung-hyperinflation
#10
William Spencer Cheyne, Jinelle C M Gelinas, Neil Derek Eves
Dynamic hyperinflation (DH) is common in COPD and is associated with dyspnea and exercise intolerance. DH also has adverse cardiac effects, though the magnitude of DH and the mechanisms responsible for the hemodynamic impairment remain unclear. We hypothesized that incrementally increasing DH would systematically reduce left-ventricular (LV) end diastolic volume (LVEDV) and stroke volume (LVSV) due to direct ventricular interaction (DVI). Twenty-three healthy subjects (22{plus minus}2yrs) were exposed to varying degrees of expiratory loading to induce DH such that inspiratory capacity (IC) was decreased by 25, 50, 75 and 100%, (100% DH = IC of resting tidal volume plus inspiratory reserve volume ≈0...
May 4, 2018: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/29716706/systolic-aortic-regurgitation-in-rheumatic-carditis-mechanistic-insight-by-doppler-echocardiography
#11
Jagdish C Mohan, Vishwas Mohan, Madhu Shukla, Arvind Sethi
BACKGROUND: Aortic regurgitation (AR) usually occurs in diastole in presence of an incompetent aortic valve. Systolic AR is a rare phenomenon occurring in patients with reduced left ventricular systolic pressure and atrial fibrillation or premature ventricular contractions. Its occurrence is a Doppler peculiarity and adds to the hemodynamic burden. AIM: Rheumatic carditis is often characterised by acute or subacute severe mitral regurgitation (MR) due to flail anterior mitral leaflet and elongated chords...
March 2018: Indian Heart Journal
https://www.readbyqxmd.com/read/29713818/right-ventriculo-arterial-uncoupling-and-impaired-contractile-reserve-in-obese-patients-with-unexplained-exercise-intolerance
#12
Colm McCabe, Rudolf K F Oliveira, Farbod Rahaghi, Mariana Faria-Urbina, Luke Howard, Richard G Axell, Andrew N Priest, Aaron B Waxman, David M Systrom
BACKGROUND: Right ventricular (RV) dysfunction and heart failure with preserved ejection fraction may contribute to exercise intolerance in obesity. To further define RV exercise responses, we investigated RV-arterial coupling in obesity with and without development of exercise pulmonary venous hypertension (ePVH). METHODS: RV-arterial coupling defined as RV end-systolic elastance/pulmonary artery elastance (Ees/Ea) was calculated from invasive cardiopulmonary exercise test data in 6 controls, 8 obese patients without ePVH (Obese-ePVH) and 8 obese patients with ePVH (Obese+ePVH) within a larger series...
April 30, 2018: European Journal of Applied Physiology
https://www.readbyqxmd.com/read/29706899/development-of-the-human-placenta-and-fetal-heart-synergic-or-independent
#13
REVIEW
Graham J Burton, Eric Jauniaux
The placenta is the largest fetal organ, and toward the end of pregnancy the umbilical circulation receives at least 40% of the biventricular cardiac output. It is not surprising, therefore, that there are likely to be close haemodynamic links between the development of the placenta and the fetal heart. Development of the placenta is precocious, and in advance of that of the fetus. The placenta undergoes considerable remodeling at the end of the first trimester of pregnancy, and its vasculature is capable of adapting to environmental conditions and to variations in the blood supply received from the mother...
2018: Frontiers in Physiology
https://www.readbyqxmd.com/read/29698407/a-novel-echocardiographic-hemodynamic-index-for-predicting-outcome-of-aortic-stenosis-patients-following-transcatheter-aortic-valve-replacement
#14
Altayyeb Yousef, Benjamin Hibbert, Joshua Feder, Jordan Bernick, Juan Russo, Zachary MacDonald, Christopher Glover, Alexander Dick, Munir Boodhwani, Buu-Khanh Lam, Marc Ruel, Marino Labinaz, Ian G Burwash
OBJECTIVE: Transcatheter aortic valve replacement (TAVR) reduces left ventricular (LV) afterload and improves prognosis in aortic stenosis (AS) patients. However, LV afterload consists of both valvular and arterial loads, and the benefits of TAVR may be attenuated if the arterial load dominates. We proposed a new hemodynamic index, the Relative Valve Load (RVL), a ratio of mean gradient (MG) and valvuloarterial impedance (Zva), to describe the relative contribution of the valvular load to the global LV load, and examined whether RVL predicted patient outcome following TAVR...
2018: PloS One
https://www.readbyqxmd.com/read/29696409/valvular-heart-disease-and-pregnancy
#15
REVIEW
Emily S Lau, Nandita S Scott
With improving reproductive assistive technologies, advancing maternal age, and improved survival of patients with congenital heart disease, valvular heart disease has become an important cause of morbidity and mortality in pregnant women. In general, stenotic lesions, even those in the moderate range, are poorly tolerated in the face of hemodynamic changes of pregnancy. Regurgitant lesions, however, fare better due to the physiologic afterload reduction that occurs. Intervention on regurgitant valve preconception follows the same principles as a non-pregnant population...
April 26, 2018: Current Treatment Options in Cardiovascular Medicine
https://www.readbyqxmd.com/read/29689088/electrocardiogram-synchronized-pulsatile-extracorporeal-life-support-preserves-left-ventricular-function-and-coronary-flow-in-a-porcine-model-of-cardiogenic-shock
#16
Petr Ostadal, Mikulas Mlcek, Holger Gorhan, Ivo Simundic, Svitlana Strunina, Matej Hrachovina, Andreas Krüger, Dagmar Vondrakova, Marek Janotka, Pavel Hala, Martin Mates, Martin Ostadal, James C Leiter, Otomar Kittnar, Petr Neuzil
INTRODUCTION: Veno-arterial extracorporeal life support (ECLS) is increasingly being used to treat rapidly progressing or severe cardiogenic shock. However, it has been repeatedly shown that increased afterload associated with ECLS significantly diminishes left ventricular (LV) performance. The objective of the present study was to compare LV function and coronary flow during standard continuous-flow ECLS support and electrocardiogram (ECG)-synchronized pulsatile ECLS flow in a porcine model of cardiogenic shock...
2018: PloS One
https://www.readbyqxmd.com/read/29688911/tranilast-blunts-the-hypertrophic-and-fibrotic-response-to-increased-afterload-independent-of-cardiomyocyte-transient-receptor-potential-vanilloid-2-channels
#17
Sheryl E Koch, Michelle L Nieman, Nathan Robbins, Samuel Slone, Mariah Worley, Lisa C Green, Yamei Chen, Alexandria Barlow, Michael Tranter, HongSheng Wang, John N Lorenz, Jack Rubinstein
Tranilast is clinically indicated for the treatment of allergic disorders and is also a non-selective blocker of the Transient Receptor Potential Vanilloid 2 (TRPV2) channel. Prior studies have found that it has protective effects in various animal models of cardiac disease. Our laboratory has found that genetic deletion of TRPV2 results in a blunted hypertrophic response to increased afterload, thus this study tested the hypothesis that tranilast through cardiomyocyte TRPV2 blockade can inhibit the hypertrophic response to pressure overload in-vivo via transverse aortic constriction and ex vivo via isolated myocyte studies...
April 20, 2018: Journal of Cardiovascular Pharmacology
https://www.readbyqxmd.com/read/29677035/outflow-cannula-systolic-slope-in-patients-with-left-ventricular-assist-devices-a-novel-marker-of-myocardial-contractility
#18
Jonathan Grinstein, Eric Kruse, Gabriel Sayer, Gene H Kim, Jayant Raikhelkar, Sara Kalantari, Nitasha Sarswat, Sirtaz Adatya, Takeyoshi Ota, Valluvan Jeevanandam, Victor Mor-Avi, Roberto M Lang, Nir Uriel
Left ventricular (LV) unloading with a LV assist device (LVAD) reverse remodels the heart and may lead to favorable changes in cellular architecture and LV geometry promoting myocardial recovery. Currently, there are no standardized methods for evaluating myocardial recovery. This study assesses the systolic slope of the LVAD outflow cannula as a marker for myocardial contractility. Doppler echocardiography (transthoracic echocardiogram [TTE]) of the LVAD outflow cannula and TTE of the LV cavity were prospectively collected in 57 patients with LVADs...
April 18, 2018: ASAIO Journal: a Peer-reviewed Journal of the American Society for Artificial Internal Organs
https://www.readbyqxmd.com/read/29657057/ventricular-efficiency-in-pregnant-women-with-congenital-heart-disease
#19
Jun Muneuchi, Keiko Yamasaki, Mamie Watanabe, Azusa Fukumitsu, Takeshi Kawakami, Hiromasa Nakahara, Kunitaka Joo
BACKGROUNDS: Pregnant women with congenital heart disease (CHD) are at risk of cardiovascular events during pregnancy as well as postpartum. The aim of our study is to address the feasibility of echocardiography-derived ventricular-arterial coupling during pregnancy and postpartum among women with CHD. METHODS: In 31 pregnant women with CHD, we performed serial echocardiography at the first and third trimesters, early and late postpartum. The indices of contractility (single-beat determined end-systolic elastance, Eesab ) and afterload (effective arterial elastance, Ea) were approximated on the basis of the systemic blood pressure and systemic ventricular volume...
June 15, 2018: International Journal of Cardiology
https://www.readbyqxmd.com/read/29649954/anatomical-considerations-and-open-surgery-to-treat-juxtarenal-abdominal-aortic-aneurysms
#20
Georgiana Samoila, Ian Michael Williams
INTRODUCTION: Historically, the open approach to the abdominal aorta has been transperitoneal (TP). In comparison, a retroperitoneal (RP) incision exposes the lateral wall of the suprarenal aorta for clamp application and midline structures such as the duodenum and pancreas are not encountered. Proximal clamp position for open repair of juxtarenal abdominal aortic aneurysm (JR-AAA) is suprarenal, supra-superior mesenteric, or supraceliac. While RP and TP approaches have previously been compared for physiological reasons, there are currently no randomized controlled trials comparing these methods from an anatomical perspective...
January 1, 2018: Vascular and Endovascular Surgery
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